Traditional high volume manufacture and assembly of machines and vehicles has occurred in large assembly plants. These assembly plants have included multiple assembly lines where components are gathered, assembled and connected together. In the manufacture and assembly of vehicular bodies, the bodies typically include a skeleton of sheet metal components that are welded together through resistance spot welding, seam welding and brazing techniques to form what are commonly called “body-in-white” (BIW) structures.
With the growing need to efficiently build vehicles and accommodate varying consumer demand, assembly plants have strived to employ flexible build processes so that different vehicles, or vehicle bodies, can be built along the same assembly lines. The ability to quickly change over from building one type of body to another causes significant difficulty for facilities due to the limited amount of space around assembly lines and the time required to change over equipment and components that are specific to one vehicle body.
Due to these difficulties in logistics and time, manufacturers have employed either batch-type vehicle builds where a certain number of one vehicle body is assembled before changing the equipment and components so a different vehicle body can be assembled. In order to accomplish this, bins or racks containing many individual components or subassemblies specific to a particular vehicle were positioned next to an assembly cell or build station along the assembly line. As shown in FIGS. 1 and 2, if, for example, different vehicle bodies A, B and C were to be built, bins for storing or staging components for a build cell specific to a vehicle body would have to be positioned proximate to the build station. On changing from one vehicle type to another, for example for vehicle type A to vehicle type B, the bin A would have to be moved aside so the bin containing the B vehicle-type components could be positioned next to the assembly cell for convenient transfer by hand or automated robot. Where three, four or more different vehicles types are built along an assembly line, it is problematic and burdensome to logistically keep many bins of different parts next to each assembly cell. This causes congestion on the plant floor and further complicates the changeover process.
Alternately, and in a further effort to meet varying consumer demand, vehicle builds were conducted in a random build sequence where every next vehicle to be built was different than the one prior. Such random build sequences required coordinating the sequencing of build parts in a particular part rack to match the selected vehicle build sequence. For example as generally shown in FIG. 3, if a body type A was to be built followed by a body type B, then C, an individual bin at an assembly cell would include parts A, B and C organized or staged in the bin in the specific order the vehicles were to be built. An example of this sequenced bin is shown in FIG. 1. This required significant planning, coordination and staging of the parts in the individual bins prior to delivery to the assembly line and careful selection of the parts from the bin on the assembly line to ensure the proper vehicle specific part was removed from the bin and used in the assembly cell. Such coordination and staging was time consuming, costly and susceptible to a high occurrence of error.
Thus there is a need to improve on the system for efficiently achieving the desired random build sequence that reduces or eliminates the above difficulties and problems.